Clinicopathological characteristics of incidental parathyroidectomy after total thyroidectomy: The effect on hypocalcemia. A retrospective cohort study.

BACKGROUND

The reported rate of incidental parathyroidectomy (IP) during total thyroidectomy varies between 6.4 and 31.1%. The aim of this study was to investigate the clinicopathological characteristics associated with IP.

MATERIALS AND METHODS

This is a retrospective cohort study which included 2556 patients who underwent total thyroidectomy between 2002 and 2012 at a single tertiary institution. Demographics, clinicopathological risk factors, and postoperative calcium levels were compared between IP and control group.

RESULTS

Incidental parathyroidectomy occurred in 18.3% of patients. IP patients had higher risk of postoperative biochemical (40.3% vs 17.3%, p < 0.001) and symptomatic hypocalcemia (14.3% vs 7.3%, p < 0.001) than no-IP group. Multivariate analysis showed malignancy, tumor size >10 mm, thyroid capsule invasion, extrathyroidal extension, lymph node metastases and central neck dissection, operation time, RLN injury, thyroid gland dimensions were independent risk factors for IP.

CONCLUSIONS

Our results indicate that patients with certain preoperative findings such as larger thyroid dimensions, diagnosis of malignancy and especially tumor >10 mm, extrathyroidal extension, and lymph node metastasis are at higher risk of IP and postoperative symptomatic hypocalcemia and these patients should be adequately informed and treated. Α meticulous intraoperative identification and the preservation of all parathyroid glands results in lower incidence of IP and postoperative hypocalcemia.